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All posts for the month March, 2011

Finally today I had implemented NIC bounding (bind both NIC so that it works as a single device). We have two Dell servers that need setup with Intel Dual Gig NIC. My idea is to improve performance by pumping out more data from both NIC without using any other method.

This box act as heavy duty ftp server. Each night I need to transfer over 200GB data from this box to another box. Therefore, the network would be setup is two servers on a switch using dual network cards. I am using Red Hat enterprise Linux version 4.0.

Linux allows binding multiple network interfaces into a single channel/NIC using special kernel module called bonding. According to official bonding documentation, “The Linux bonding driver provides a method for aggregating multiple network interfaces into a single logical “bonded” interface. The behavior of the bonded interfaces depends upon the mode; generally speaking, modes provide either hot standby or load balancing services. Additionally, link integrity monitoring may be performed.”

The version of perl (v5.8.7) is too old. There are known problems that cannot be worked around with this version of perl. It is HIGHLY recommended that you upgrade to v5.8.8 or later. Any module install failures should be ignored until perl has been upgraded as some modules will not be able to install with this version of perl.

You can ensure that each installed module gets carried over to the updated Perl build with the use of the “autobundle” CPAN feature.

You can create a bundle of the currently installed modules by executing the following while logged in via SSH as root:

perl -MCPAN -e ‘autobundle’

Once completed, you should see the following output before getting returned to the shell:

‘Wrote bundle file /home/.cpan/Bundle/Snapshot_2007_08_16_00.pm’

Once you’ve made note of this file name, you can proceed with the update.

On linux based systems, you should be able to update Perl using the installer provided at layer1.cpanel.net:

This will take a few minutes, so take a coffee break and check the status when you return. Once the update has completed, you can install all previously installed modules from the CPAN bundle by executing the following (with the bundle name adjusted to the name of the bundle generated earlier):

perl -MCPAN -e ‘install Bundle::Snapshot_2007_08_16_00’

This should install each of the modules present in the bundle, assuming there are no issues during the installation (dependencies, network, etc).

Once this has completed, execute the following to ensure that all modules required by cPanel are installed, and restart cPanel:

It is important to know traffic usage of your client if you’re a Linux network administrator. You can monitor your client in text mode, graphic mode or html exported like mrtg, cacti or bandwidthd and one of my favorite bandwidth monitor is Bandwidthd.

You don’t need any database or snmp connection to monitor all of your client on bandwidthd, all you need just libcap, libpng, libgd and apache installed on your Linux system. And other good news is bandwidthd monitor all of your connected client per IP and per connection protocol.

Save your config and start bandwidthd using/usr/local/bandwidthd/bandwidthd. Put that command to your /etc/rc.localfile so bandwidthd can start on every time Linux boot.

Configuring Apache

You will can’t see your graphic report until you set/usr/local/bandwidthd/htdocs/ folder to set as apache virtual directory. Add below line to your apache config file.

Alias /bandwidthd “/usr/local/bandwidthd/htdocs”
<Directory “/usr/local/bandwidthd/htdocs”>
Order Allow,Deny
Allow from All
</Directory>
Save your work and restart apache. Next open your browser and point to http://yourlinuxserver/bandwidth.